[nickbatz]

My question is, if that's true, is there's an acceptable range of give and
take between this pure sonority and sense-of-space, and if so, is there a
rule that regulates it?

On that subject, I've always differentiated between reverb on an individual instrument and overall space reverb. And by "always," I mean it's not something I've ever questioned - it just seems evident that some reverb processors and programs stick to certain instruments, and some don't.

For example, trying to find a good reverb for a solo flute or sine wave-ish synth sound isn't always easy.